[RIA VR80 coming in 2019]

Had a literal blast today with offseason things. One part was trying to capture on film how the midbarrel comp and muzzle brake work for real.

I have a lot of editing and evaluation to do tomorrow. Oh, i also shot some black powder cartridges..

 

[RIA VR80 coming in 2019]

Did another recoil pattern evaluation. Last one was around Christmas.

Shown in 5% speed and in realtime.

The pattern was pretty much the same with 28g (1oz) and with 32g (1.1oz). As i am shooting these offhanded i'm pretty certain that my shooting technique affects to most of the movement. Building a setup that would legitimately show the barrel rise would be too much work. 

At least it's a reference point for training. I should do this again after 3 months.

 

As a side note. The barrel rise offhanded is 27mm (1"). 

 

 

 

[RIA VR80 coming in 2019]

On 3/21/2020 at 3:36 AM, WWG1WGA said:

...

 

Nice!

 

I presume that you have changed to a rifle buffer tube? That opens up a lot more possibilities weight and spring wise.

I did not include the buffer spring in to the weight and the 70g is about as heavy i can go at the moment.

 

For some reason competition buckshot has a lot less force for cycling behind it than my competition birdshot.

From slow motion footage i have gathered that with this spring and buffer weight it's just in the limit of cycling with 2 midbarrel holes blugged at around 0C° (32F°).

[RIA VR80 coming in 2019]

4 minutes ago, Nelsonh said:

Me too

Sent from my Moto E (4) using Tapatalk
 

 

Sorry. Misunderstood your message. I thought you were thinking about it.

 

Or were you commenting on this "I wish the Turks would of made something on this shotgun to AR-spec. "

[RIA VR80 coming in 2019]

1 hour ago, Nelsonh said:

If I can find it I used to have one of the at bianary triggers, may more the hammer and disconnector to work in the VR and see what that's like with this light recoil lol.

Oh the at hammer is to short and not wife enough to teach the firing pin and the disconnector will hit the hammer before cocking. Can probably just modify the hammer just above the disconnector hook and it should work just fine in the vr80

Sent from my Moto E (4) using Tapatalk
 

 

Here is my trigger assebly from about 5 months ago. I have taken some material off from the surfaces shown by arrows after this picture was taken.

I aso polished the surfaces that are connecting between each other during the cokcing process. Now i can barely notice the binding when cycling by hand, hammer forward while pressing the trigger.

 

I have no data on paper but it feels smoother and the recoil is more consistent.

 

Also in the picture are the JP springs, Adapter for the JP spring on the hammer, my own trigger and OR anti-walk pins.

If i had money i would find or have made for me closer to 4mm diameter pins and the hammer pin should be about 5mm longer than the trigger pin.

 

I wish the Turks would of made something on this shotgun to AR-spec.

[RIA VR80 coming in 2019]

32 minutes ago, Nelsonh said:

Ok it seems that adding weight to the buffer does decrease felt recoil a lot but can make the gun finicky.
What I did was weld a 8 ox pice of metal to the carrier (forgot to account for the weld) so now my gun won't cycle 00buckdhot at 1345 fps.
I'll start trimming and weighing till I get to what I want to shoot

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Or make a buffer with adjustable weights? The original is 41g. This setup is about 70g.

[RIA VR80 coming in 2019]

18 hours ago, meeesterpaul said:

I saw a video where someone tested 5 muzzle brakes. They had very interesting results and a bunch of people said I want that VP unit. Then someone said oops your calculations are off, the other one the GK 03 should have won. Here is a recent email they sent me saying that they have them in stock again. https://ivantactical.com/shop/weapon-accessories/weapon-rails-and-tuning/muzzle-devices/akademia-vepr-12-ilyin-gk-03-muzzle-brake/
I'm just going to go with porting.

 

I think they should take in to account the weight of the muzzle brakes they are testing. Usually they are testing barrel rise on a bench with some grid paper behind.

The GK-03 weighs "just" 208g. 8g heavier then the first muzzle brake I had on my Derya for the first year. It was a copy of this made to fit the MK-12: https://www.atlanticfirearms.com/products/x12-shotgun-compensator.

 

Of course they will affect barrel rise if there is a hunk of metal at the end of a 20" pole. My scrawny wrist had it's work cut out to it every time i had to back up (run backwards) on a stage.

 

In my opinion the best test would be to measure the directional force of directed gasses from the brake. I have seen some flow simulations made with some common brakes but i don't know how accurate they are.

 

I have limited skills in math but i used this to make my own brake: https://apps.dtic.mil/dtic/tr/fulltext/u2/838748.pdf

[RIA VR80 coming in 2019]

9 minutes ago, Nelsonh said:

What size holes do you use for porting? And how many?
Does it cause any issues with the plastic wadding?

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Picture below. Measurements in millimeters.

I haven't seen any plastic residue inside the comp or the ports if that's what you mean.

 

I have to make up my mind but at the moment I'm thinking about bigger but fewer holes in a different configuration.

[RIA VR80 coming in 2019]

Just now, AverageJoeShooting said:

I guess. V6 is supposed to be coming out with a mid barrel break at some point. I imagine that would make then chop the barrel down 

 

Mid barrel comp works better with longer barrel shotguns then a muzzlebrake because of the gas pressure differential in different parts of the barrel.

Using both to capture all the gas available is not wrong in my opinion.

I have my own mid barrel comp that works well, but i will probably redesign it according to the barrel area i have to work with.

[RIA VR80 coming in 2019]

2 minutes ago, AverageJoeShooting said:

All I know Is that shorter barrel means less distance for the gas to dissipate from which means more recoil 

 

Not a major issue. Of course i will port the barrel and place my brake to the end of the muzzle.

More gasses with higher velocities for the brake to work with = profit?

[RIA VR80 coming in 2019]

I'm having some talks with our national supplier for Derya here in Finland about ordering me a new barrel and parts related for 2021 season.

After about 7k rounds the chroming or some other surface coating has started to chip away from the barrel where the gasses flow.

 

I had the idea last night that might as well order up a shorter barrel. I have scrounged the internet for information on the effects of barrel length on a shotgun but with little luck.

Most of the topics revolve around 20"-28" barrels. Barrels that could be available for me are 14" and 16".

I suppose the 16" barrel would be the safest choice.

 

I'm mainly concerned that i would not fulfill the PF requirements in IPSC shooting. My main competition ammo for birdshot is 28g (1oz i believe in American). Second thing would be the shot patterns with birdshot/buckshot and accuracy with slugs to 100m (about 110yd).

 

Also my competition rifle has a 16" barrel so that would bring some uniformity to grip lengths and handling.

 

Does anyone here have any hands on experience with shorter shotgun barrels?

 

Pictures of shotguns with 14" and 16" barrels that i'm trying to get the barrels from below.

[RIA VR80 coming in 2019]

5 minutes ago, AverageJoeShooting said:

What muzzle break is that 

 

Haven't thought about it. Suggestions are allways welcome.

It's my own design. Everything visible in wine red is. Excluding the palm rest and that thing that holds the hand guard in place.

[RIA VR80 coming in 2019]

Hello everyone!

 

I have been lurking here for about 6 months and decided to share a few photos of my completed (for this season) Derya MK-12.

Derya MK-12 is basically the European and original version of the VR80.

Hope you enjoy the pictures.